Chris Pratt took to social media to share an adorable video of his 4-year-old son Jack along with a heartfelt message on World Prematurity Day, which was celebrated on 17 November. Jack was a premature baby when The Guardians of the Galaxy actor and his wife, Anna Faris welcomed him into the world.

Although the 37-year-old actor's son was "just over 3 pounds when he was born", the little one has grown up fit and healthy with the support of March of Dimes, a nonprofit organisation that strives on improve the health of mothers and babies.

"As many of you may know, our son Jack was just over 3 pounds when he was born. Thanks to scientific advances made possible by #marchofdimes funding, today he's a perfectly healthy, curious 4 year old," Pratt wrote on Instagram.

"Today is #worldprematurityday. 15 million babies are born #prematurely each year around the world. And 1 million of them won't live to celebrate their 1st #birthday," Pratt said.

"The @marchofdimes strives for a world where every #baby has a fair chance, yet this is not the reality for many mothers and babies. Join me in supporting their efforts to give every baby a fighting chance by clicking the link in my bio. Thank you!" he concluded.

Pratt, in his speech at the non-profit organisation's luncheon in 2014, had said that after he and his wife welcomed their son he prayed the little one lived "long enough that I could keep them".

"Our Jack went from a small, helpless little squirt to a strong, smart, happy, funny, beautiful boy who loves monster trucks and Daniel Tiger, and, believe it or not, loves vegetables," Pratt had said. (Via E!News) "Broccoli and cherry tomatoes are his favorite foods."

As many of you may know, our son Jack was just over 3 pounds when he was born. Thanks to scientific advances made possible by #marchofdimes funding, today he's a perfectly healthy, curious 4 year old. Today is #worldprematurityday. 15 million babies are born #prematurely each year around the world. And 1 million of them won’t live to celebrate their 1st #birthday. The @marchofdimes strives for a world where every #baby has a fair chance, yet this is not the reality for many mothers and babies. Join me in supporting their efforts to give every baby a fighting chance by clicking the link in my bio. Thank you! God Bless!!!

A video posted by chris pratt (@prattprattpratt) on